During my combined residency in Internal Medicine and Pathology, I developed an interest in the pathogenesis of the rheumatic diseases. After one year as a clinical fellow in Rheumatology, I entered the laboratory of Dr. Laurie Glimcher. My intent was to learn the basic tools of molecular biology. Ultimately, I plan to combine these tools with my knowledge of pathology, to approach an understanding of rheumatic disease. The proposed project will allow me to master the techniques of the field, disease. The proposed project will allow me to master the techniques of this field, while also addressing critical questions regarding the triggering and amplification of tissue destruction in connective tissue disease. Aberrant expression of class II major histocompatibility complex proteins is a prominent feature in autoimmunity. Such expression is present in synovium, proximal tubules, thyroid, pancreatic islets, and other tissues in a variety of autoimmune states. Although it is not known whether aberrant class II expression is the initial event or a secondary phenomenon potentiating the autoimmune process, preliminary evidence suggests that in some disease states, increased levels of class II precede tissue destruction. Lipopolysaccharide (LPS) is known to induce class II expression in a number of cell types, and in autoimmune states. We have identified a nuclear factor, NF-LPS, in nuclear extracts prepared from mouse spleen. NF-LPS is inducible upon stimulation with LPS and binds to two sequences in the upstream regulatory region of the mouse Aalpha class II gene. Initially we will concentrate on the characterization of this protein and its binding sites. Subsequently we will obtain a cDNA clone coding for this protein from a lambda(gt11) expression library. Antibody to the protein can then be prepared. Once obtained, these reagents will be used to study the role of NF-LPS in the induction of class II in an animal model of uveitis. The eventual goal is to selectively manipulate NF-LPS activity such that aberrant class II expression and subsequent tissue destruction is prevented. Dr Glimcher's laboratory already has expertise in the techniques needed for this project, and has recently been successful in cloning several proteins binding to regulatory regions of DRalpha and Aalpha genes. This laboratory will be an excellent environment in which to achieve my outlined goals.